From the Guidelines
Taking vitamin D 50,000 IU daily for a week is not a recommended standard regimen and may lead to vitamin D toxicity. This high dosage is typically reserved for treating severe vitamin D deficiency under medical supervision, as indicated in the study by 1. A more common therapeutic approach for significant deficiency is 50,000 IU once weekly for 6-8 weeks, followed by maintenance therapy. Daily doses of vitamin D for most adults should range from 600-2,000 IU for maintenance, as suggested by 1.
Some key points to consider:
- The recommended daily allowance for vitamin D in individuals over 60 years is 800 IU, and for younger adults 400 IU, according to 1.
- Vitamin D toxicity can occur with daily doses of more than 50,000 IU per day, producing 25(OH)D levels larger than 150 ng/mL, as noted in 1.
- The NCCN Bone Health in Cancer Care Task Force recommends 1200 mg of calcium and 800 to 1000 IU of vitamin D daily for adults older than age 50, as stated in 1.
- Measurement of 25(OH)D and subsequent supplementation if <30 ng/mL is recommended for all individuals, with a large correcting dose proposed initially, followed by a maintenance treatment, as suggested by 1.
The most appropriate approach is to have vitamin D levels checked through a blood test and follow a healthcare provider's specific recommendations for supplementation based on individual needs and current vitamin D status, as implied by the studies 1.
From the Research
Vitamin D Supplementation
- The use of vitamin D supplements has increased substantially over the last decade, with epidemiologic evidence linking vitamin D deficiency to various illnesses, including autoimmune disease, cancer, and cardiovascular disease 2.
- The Institute of Medicine has concluded that vitamin D supplementation for indications other than musculoskeletal health is not adequately supported by evidence, and that most North Americans receive sufficient vitamin D from their diet and sun exposure 2.
Daily Oral Dosing of Vitamin D3
- A study has shown that long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe, with no cases of vitamin D3-induced hypercalcemia or adverse events attributable to vitamin D3 supplementation 3.
- The study found that three patients with psoriasis showed marked clinical improvement in their skin using 20,000 to 50,000 IUs/day of vitamin D3 3.
Vitamin D Deficiency and Supplementation
- Vitamin D deficiency is associated with unfavorable skeletal outcomes, including fractures and bone loss, and a 25(OH)D level of >50 nmol/L or 20 ng/ml is the primary treatment goal 4.
- Severe vitamin D deficiency with a 25(OH)D concentration below <30 nmol/L (or 12 ng/ml) dramatically increases the risk of excess mortality, infections, and many other diseases, and should be avoided whenever possible 4.
- Vitamin D supplementation may be an important, inexpensive, and safe adjuvant therapy for many diseases, but future large and well-designed studies are needed to evaluate this further 4.
Calcium and Vitamin D
- Calcium and vitamin D are essential for maintaining calcium homeostasis and skeletal integrity, and have important roles in non-skeletal-related physiological processes 5.
- Significant proportions of some population groups fail to achieve the recommended calcium intakes, and vitamin D is found naturally only in a limited number of foods, making supplementation necessary to maintain adequate vitamin D status 5.
- Deficits in calcium and vitamin D increase the risk of various common chronic diseases, including skeletal disorders, malignancies, and metabolic disorders 6.